Patent GB-738161-A (GB)
Title: Improvements in and relating to the production of oxygen-containing organic compounds
Inventor: TAYLOR ARTHUR WILLIAM CHARLES
IPC: C07C27/22
Filed: 1952-04-02
Abstract: Oxygen-containing compounds are produced by a process of continuous carbonylation of olefines with carbon monoxide and hydrogen at elevated temperature and pressure in the presence of a dissolved cobalt catalyst, and simultaneously decomposing cobalt compounds dissolved in the carbonylation product and precipitating the cobalt as metal by treatment of the product in a decomposition zone with hydrogen at elevated temperature and pressure, characterized in that the optimum temperature is maintained in the decomposition zone by providing between the main reactor and the decomposition zone an auxiliary zone in which 2-15 per cent further carbonylation takes place whereby heat is evolved and the amount of further carbonylation is controlled so that the liquid entering the decomposition zone is maintained at the desired temperature.  Control of the further carbonylation in the auxiliary zone may be achieved by variation of the liquid feed rate to, and take-off rate from, the main reaction to ensure that only say 85-90 per cent of the carbonylation takes place there. Alternatively, up to 15 per cent of the olefine feed, preferably containing dissolved cobalt catalyst, may be bypassed to the auxiliary zone and directly carbonylated there with additional carbonylating gas.  The preferred temperatures are 110-150 DEG  C. at the inlet and 110-180 DEG  C. at the outlet of the main reactor, and 150-170 DEG  C. at the decomposition zone outlet.  Both zones are preferably operated at 200-300 atm. gauge, the decomposition zone being at a slightly lower pressure than the main reactor.  The dissolved cobalt catalyst may be the acetate, nonanoate, oleate, butoxy-butyrate, hexahydrobenzoate or naphthenate.  The auxiliary vessel is preferably a gas/liquid separation vessel or catchpot but may be an additional high-pressure vessel.  The size of the auxiliary zone should be such that the residence time therein does not exceed 15 per cent of the residence time in the main reactor. The process is particularly suitable for alkenes-1 having up to 12 carbon atoms.  In examples: (1) di-isobutene is carbonylated in the presence of cobalt naphthenate; a catchpot having a capacity of 5 per cent of the main reactor is the auxiliary zone; the rates of flow to and from the main reactor are adjusted to give 4 per cent carbonylation in the catchpot and the temperature at the decomposition zone outlet is 150 DEG  C.; (2) in the carbonylation of a C6-C8 alkene mixture, 10 per cent of alkene containing catalyst is by-passed to a catchpot on the exit side of the reactor with additional carbonylating gas, the further reaction raising the inlet temperature of the decomposition zone to 160 DEG  C.; (3) propylene is carbonylated in a reaction medium of ethers, esters and alcohols containing 10 or more C atoms and boiling at 180-200 DEG  C., and liquid propylene is injected, at a volume rate of 7.5 per cent of the main feed, into a catchpot together with additional carbonylating gas wherein the heat evolved raises the decomposition zone outlet temperature to 160 DEG  C.  According to the Provisional Specification, the further conversion may take place in the pipe line between the main reactor and the decomposition.